Plug and socket.



J. N. DAVIS.

PLUG AND SOCKET.

APPLICATION FILED FEB. I6. I9I4.

Patented Mar. 14, 1916.

3 SHEETS-SHEET 2- J. N. DAVIS.

PLUG AND SOCKET.

APPLlcATloN FILED FEB. 16. 1914.

Patented Mar. 14, 1916.

illlllllll @ULg-J- 1. N. DAVIS..

PLUG AND SOCKET.

APPLlcATloN FILED FEB.16.1914.

Patented Mar.'14, 1916.

3 SHEETS-SHEET 3.

earner carica.

sra

JASPER NQDVIS, OF DENVER, COLORADO.

PLUG AND SOCKET.

' charging the storage batteries of electrically operated vehicles.

My present construction relates to certain improvements over the construction disclosed in Letters Patent No. 921,959, dated May 18, 1909; and No. 981,622, dated January 17 1911, and consists of certain novel features of construction relating to the socket-containing block and the removable plug, either in the form of the wall socket and plug, or the socket and` plug employed upon the vehicle, all of which will be ully understood by reference to the accompanying drawing, in which is illustrated an embodiment thereof.

The particular feature of my present improvement relates to a special construction, whereby the plug is readily removable from the socket in any direction Without injuring the contacts carried by the socket block and which are engaged by the electrodes of the plug. This I accomplish by forming bearing recesses, or cavities, in the block, both above and below the socket contacts and adapted to receive bearing projections formed on the plug, the said cavities having their bottoms approximately in a plane midway of the block contacts, whereby when the plug is removed by using either the uper or lower projection, as a fulcrum, the plug electrodes escape rom the socket block contacts by nearly a straight pull, thus preventing injury to the contacts, as would result if the fulcrum bearings were differently located. Forinstance, if the fulcrum bearingswere such as to cause the electrodes to move in a curve described by a relatively long radius, the tendency would be to move the electrodes toward one of the block contacts and in engagement therewith for a relatively long distance, thus having a tendency. to separate the two spring contacts which coperate with each electrode in completing the charging circuit, considerably. Under these circumstances, the block contarts become gradually weakened by repeated pressure in a direction to separate them,

Specication of Letters Patent.

moved from the contacts of the block by a lateral thrust in either direction without undue injury to the spring contacts of the block. In this case, the ulcrum is a shoulder on the block which coperates with themeeting shoulder of the plug, these two shoulders engaging each other on each side of the block and plug. It may be further stated, that the removal of the plug from the block may be readily accomplished by a thrust m any direction, either by an upward or downward movement, or by a lateral movement, or a movement in a diagonal direction, in which a corner of the plug engages a corner of the block at any one of the four corners of the latter.

Having briefly outlined my improved construction, I will proceed to describe the same in detail, reference being made to the accompanying drawing, in which is illustrated an embodiment thereof:

In this drawing: Figure 1 is a face view of the socket block or receptacle, combined with a fuse block employed in connection therewith. Fig. 2 is an. end elevation of the same. Fig. I3 is a vertical section. taken through the combined socket and fuse block, showing the socket plug in place and partly in section. Fig. 4 is a side elevation, showing a socket block such as is used on a vehicle, and a socket plug in operative connection therewith, the block being provided with an acidshielding cap. Fig. 5 is a front view of the socket block, shown in Fig. 4, the hinged door or cover being removed. Fig. 6 is a top view of the acid shield or cap. Fig. 'l' is a top plan view of the block, the acid shield being removed. Fig.l 8 is a rear view of the block, with the cap or shield attached. Fig. 9 is a perspective view of a soft rubber protector adapted to close the circuit openings in the block. Fig. 10 is a front view of a clamping plate adapted to hold the rubber protectors firmly against the circuit openings of the block. VFig. 11 is a vertcal'sectiontaken through the clamp Patented Mar. Mt, 19t@ Application led February 16, 1914. Serial 1%. 819,005.

tical longitudinal section of the socket and plug, in circuit-closing relation, showing the socket contacts and plug electrodes in engagement, and the respective circuit wires connected therewith. Fig. 13 is a plan view of the under side of the plug. Fig. 14 is a horizontal sectional view taken through the center of the plug and parts carried thereby. Fig. 15 is an end view of the plug shown in Figs. 13 and 14. Fig. 16 is a side view of one-of the contact lugs or electrodes, shown in Figs. 14 and 15. Figs. 17 and 18 are side and end views, respectively, of the base plates in which are seated the spring contacts and the electrodes. Figs. 19 and 20 are side and end views, respectively, of the circuit terminal connectors used in the block and plug. Fig. 21 is a perspective view showing the position of the charging block or receptacle, with respect to the battery. Fig. 22 is a perspectlve View of a circular form of contact, the wall thereof being provided with longitudinal slits`to form a corresponding number of spring jaws. Fig. 23 is a .perspective view of a square form of contact which is slit along its four corner edges to produce four spring jaws.

Referring first more particularly to Figs. 1 to 3 inclusive, let the numeral 5 designate the combined socket block and fuse block, the same being formed of an integral piece of suitable material, as porcelain. The socketblock member 6 of the device is equipped with two recesses, or cavities 7. In each of the cavities 7 is located a spring contact 9, composed of a pair .of spring arms 10, formed integral with the base 12.

Each of these contacts isv secured to the vsocket block by means of a screw 13, whose may be formed. Thespring contacts 9 are separated by an inner wall, located between the two cavities 7, in which is formed a recess 8, which opens into the adjoining cavity 7. This recess is adapted to receive a tongue 17 formed on the socket plug18, the

said tongue extending to one side of Fthe center of the block, 'and being formedl to fit the said recess. This tongue is interposed between metal electrodes 20, with which the socket plug is equipped, the said electrodes being adapted to engage the spring contacts 9 of the socket block when the plug and block are in assembled relation. The tongue 17 is formed partly of insulating material which forms the core of the plug, and partly of a metal cap 17A, having a stem 17B which is embedded in the insulating material,

which forms the core of the plug as heretofore explained, the cap 17A extending out over the end of the portion 17 of the stem,

` as shown in Fig. 14.

By virtue of the location of the tongue 17 at one side of the center of the block, it becomes impossible to apply the plug to the block in such a way as to make the electrodes interchangeable in the springfcontacts. This is an important feature, since it is impracticable to interchange the yelectrodes, as the plug-and block vare so wired that such interchangeability is not permis-y sible, sincethe corresponding positive and negative wires must coincide in the block and plug in order to maintain the proper polarity of the circuit. Furthermore, the tongue 17 forms a sort of barrier between the two electrodes and their corresponding contacts, whereby possible arcing between the electrodes and the contacts during the operation of inserting and removing the plug is prevented.

The socket block is provided above and below the recess 8 and the cavities 7 with recesses 21 and 22, adapted to receive bearing projections 23 and 24, formed on the socket plug.

In using the terms upper and lower in the foregoing statement, it is assumed that when the plug and block are assembled, that the plug occupies a horizontal position, while the block isin the position illustrated in Fig. 3, that is to say, with its member 6 below the fuse block member 4. This is the usual or ordinary manner of arranging the apparatus for charging purposes. Bearing this in mind, the manner of removing the plug from the socket will be readily understood. This may be accomplished by either lifting the plug, or bearing downwardly thereon. In either event, the fulcrum, or bearing members of the plug and block will be so arranged that the electrodes will be pulled almost straight out of their spring contact 9, thus preventing injury to the contacts. This operation is due to the fact that the recesses 21 and 22 extend inwardly toward the rearvside of the socket block, whereby the arc of travel of the electrodes is such as to produce the aforesaid result. Whereas, if the bearing parts of the plug engaged the corresponding parts of the block in a plane farther forwardly, or in the same plane with the outer extremities of t'he walls of the sockets 7 the arc of travel would be such as to cause a considerable upward and downward thrust of the side members 10 of the spring contacts in order to withdraw the electrodes from engagement with said contacts. This would also require that the sockets 7 should be made of large size in' K the socket plug, could, regardless ofthe aforesaid features of construction, be pulled directly out of the block, but this would require a great deal more exertion, and a person, in order to manipulate the plug, would need special instruction, and in the event that it were manipulated by an upward or downward thrust, the aforesaid injury to the spring contacts would result.

Attention is called to the fact that the socket plug has shoulders 25 on opposite sides (see Figs. 13, 14 and 15) adapted to engage the outer surfaces 26 of the' socket block, the said surfaces being located considerably forward of the bottom of the upper and lower recesses 21 and 22, respectively, of the block. The plug may be removed by a lateral thrust in either direction, the faces 25 of the plug respectively engaging the corresponding side parts of the block. This is permissible without injury to the spring contacts, since these contacts do not have side walls, andare consequently open at the sides to permit the lateral travel of the' electrodes in a relatively large arc.

Attention has already been called to the fact that the plug may be advantageously removed from the socket block by a corner wise thrust in any one of t'he four directions. This thrust is similar to the lateral thrust, and does not result in injury to the contacts, even though the bea-ring surfaces are located farther outwardly than the bottom of the recesses 21 and 22 respectively, of the block.

The spring contacts or clips may also bes made round with slots in the surface thereof to produce spring gripping jaws as shown by 9B, Fig. 22, or four sided with slots along the corner edges -thereof, to produce four spring jaws; as shown by 9C, Fig. 23, which would require the said recesses to be formed in the four sides of the block. When a clip or contact of the style shown in Fig. 22 is used, a correspondingly shaped electrode lwould be employed; and when a contact such as shown in Fig. 23, is used, the elec trode would be shaped to conform to this style of contact. My improved plug as shown in Figs. 3, 4, 12, and 14 differs in construction from my two previous patents in the following points: The body of the plug, or that portion which engages the vehicle socket or receptacle, consists of a metall housing 26 which is open at its forward end, and the opposite end to which the handle is secured is closed, as seen at 27. (See Fig. 15). The handle portion 28 of the plug is made of any light weight material, preferably wood, that is strong and substantial. The handle may be secured to the body 26 in any suitable way; in the drawings however, it is secured by a screw 29 which extends through the handleand screws into a lug 30, on the closed end 27. The-metal housing or bodyV compound in which is embedded the metal electrodes or contacts 20 which are clamped by the spring contacts 9 of the block or receptacle. A

In securing the electrodes rigidly in place a metal base plate 31 on which each of the electrodes 20 is heldin position, is molded into and held in place by thev insulating compound 32, Figs. 17 and 18 showing a side and an end elevation,` respectively, of one of these bases. The contact lugs 20, as shown in Fig. 16 have a flange base 33. This base is adapted to t in the'recess slot 34 in the metal base 31.- The contact lugs 20 are heldL rigidly in place against the base plates 31 by means of screws 35 which pass through the lugs 20, as shown, and also through holes in the base plate 31, and screw into wire terminal connectors 37. These wire terminal connectors 37 have their forward ends tapered, as shown,.and these tapered ends fit into correspondingly tapered holes 39 in thevback of the "metal bases 31. Therefore, a tight fitting union and electrical contact is made through the lugs 20, base 31, and wire terminal connectors 37, by meansof the above mentioned screw 35 passing through the lugs 20, base 31. and screwing into terminal connectors 37. The screws 35, have tapered heads, which fit in correspondingly tapered holes in the electrodes 20. The wire terminal connectors 37 have recesses 41 in which the terminal ends of the circuit wires 42 leading to the connectors are soldered.

Thus far, l have explained the socket and plug construction mounted on the wall of the charging plant, the combined socket and fuse block in this case being stationary.

ln Figs. 4, 5, 7, 8 and 12, the vehicle socket block 43 of the charging device is sho-wn, and this block has the same recess and spring electrodes as the face of the plug engaging portion of the socket block explained -in Figs. 1., 2 andv 3, and the plug used to engage the spring ,contact and recesses of the socket block'is identical and interchangeable with theY vehicle charging receptacle. The socket block 43` comprises a metal housing, having two hollow conical extensions 43A formed upon its rear wall. The housing and the extensions 43A are filled with a suitable insulating material 32A; the material in the housing being formed .with cavities 7A corresponding to the cavities 7 in the block 5. in the bottoms of which are embedded base plates 55, identical`in.construction with the plates 31, in the socket plugs 26, spring contacts 9A are secured to the plates 55 by screws 54 which screw into terminal connectors 56 having tapered ends which ente-r vcorresponding openings in the plates 55, the connectors 56 being the same-in construction as the connectors 37 in the socket plug 26v is filled with any suitable insulating 26. The insulating material in the eXten-v sion 43K has central passages 59 of the same from the battery on to the said receptacle.`

On most vehicles it is more convenient to have'the receptacle at thefront or rear of the car, generally the rear, and as the battery extends out the rear and front frame of the 'vehicle the receptacle is secured to the floor of the car under the battery, in

position to be acted upon by the acid from the batteries. Fig. 21 illustrates the relative position of the charging receptacle with respect to the battery support to which the receptacle is secured. The View shows the rear battery department of an electric vehicle. A battery tray is 'shown at A which contains the rear part of the battery cells. The support that carries the battery is represented by B and preferably consists vof wooden boards secured to and resting upon the frame of the vehicle represented at C. A wooden block D is secured .to the under side of the boards B, adjacent to the frame ,C of the vehicle. It is the practice of electric vehicle manufacturers to screw this block of wood D to the boards B for two reasons-rst, to lower the receptacle slightly below the ioor of the car, and also togive a firmer support for the receptacle. From the .foregoing description, it can be seen `and readily understood why the acid that seep's out of the cells, or from a broken jar, soaks through the wooden trays, and through the'support B to the charging receptacle and generally destroys it; and `to overcome-this objection, I provide my receptacle with an overhanging acid proof drainage cap 44, (see Figs. 4, 5, 8, and 12) which is secured to the receptacle, and the protec ing cap has projecting lugs 45 provided wit screw holes through which'securing screws are passed to fasten the cap to the underside of the vehicle, or as shown in Fig. 21, to theblock D. This cap maybe made of any suit-l able material that will resist the acid from the battery; I prefer, however, tomake the cap of metal, and paint or dip it in an acid proof and acid resisting solution'l that forms a coating over it and protects the metal. -This protector-cap 44, has on its l,outer edges a depending ange 47, the four corners of which form drainage -points to which the acid flows before itdrips oi. Between each two corners of the flange 47, its lower edge cinclines downwardly from a central point 48, to the adjacent corners, so that the acid runs down the inclined edges to corners of the said 'flange from V.which it drops clear of the receptacle and also of the plug, when'the same is inserted inthe rebetween the screw or bolt-holes in the lugs and the-receptacle, as shown in Fig. 6.

In Figs. 4 and 12, the receptacle with the 'plug is shown in position, a Vdoor 49 being hinged to the front of the said receptacle, and is illustrated'in the raised position and resting on the handle 28, of the plug.

Fig. 3 illustrates the connecting parts between the lsource of power and thebattery which is traced out as follows: The charging current enters the socket block 5, which is mounted on the wall of the charging station at the terminal lugs 52, and passes through the fuses 53, conductors 14, and screws 13 to the spring contacts 9,` thence through lugs 20 and bases 31 to wire terminal 37 and circuit wires 42, which connect the plugs 26 of .the socket block with the similar plug, which is inserted in the block or receptacle 43, attached to the vehicle, the current entering the terminal connectors 37 and passing to the base 31, screw 35, and lug 20, to a spring clip 9A, then to thef'screw 54, base 55, and wire terminal connector 56 to the conductors 57 leading tothe vehicle battery. The base 55 and the circuit terminal 56 in the receptacle are the same as the base 31 and the terminal connector 37 in the plug 26, and arel and a protecting attachment, whereby all l dirt and moisture is prevented from getting into the receptacle through circuit wire chambers 59, which'are formed in the insulating material. This is accomplished by a tight fitting funnel-shaped soft rubber protector 60, (see Fig. 9) slipped over the conductors 57. lA clamp 58 having conicalapertured-projections 58A, as shown in Fig.

10, iits down over the funnel-shaped rubber as illustrated in Fig. 11. The faces of the rubber protectors 60 bear against the ends of the two extensions '43A of the receptacle,

thus closing the` conductor chambers 59. By

the tightening of the screw 61, the clamping plate 58 brings a pressure on4 the two soft rubbers tightly closing up the chamber 59, at the same time squeezing the funnel end of the rubber around the two conductors by means of the tapering flange on the bracket as is shown in Fig. 11'. Thus, no. foreign matter can enter the receptacle, not even the acid, should it creep up the conductors 57 which should be hung down in a loop beforei socket block, charging receptacles and plug, i I wish to call attention to the important advantages of the same. First, the readily removing of burnt spring clips 9 and contact lugs 20. It frequently happens that a charging plug is inserted into a charging receptacle with plug connected to the ycharging circuit with the circuit closed, and the resistance cut oi, or possibly the plug wires are touching, due to insulation being worn from the wires, the result being that as soon as the plug touches the contacts of the receptacle, a short circuit is made, whereby the contacts are so badly burned that the proper connection cannot be made, and the heat of the parts burn out thereceptacle clips and plug electrodes. When either a spring clip or an electrode is burned out, the same may be renewed by taking out either the screw 54: or 35, or both, as may be required, and replaced by new ones. The next important advantage is the placing of the plug in the receptacle and removing the same. With all charging receptacles and plugs in use at the present time on electric vehicles, one can have no positive assurance, when inserting a plug into the receptacle, that a good contact can be had, or any at all. With the receptacle and plug herein described, it will Abe seen that the plug will not stay the receptacle unless it is pushed in beyond the spring clip ends, and when it is, it pulls the plug into place and a perfect contact 1s made. The plug is easily removed -from the receptacle, as heretofore explained, but wlth an electric vehicle it is a daily occurrence to have the vehicle pushed or run on its own power from its; charging position 'with the charging plug in position in the receptacle, and unless it fits very loosely (andin such cases, a" good contact is not made) the plug, receptacle, or charging wires are broken or pulled away from the wall. This will never happen during the use of my receptacle and plug, as the plug readily leaves the sprlng clips without injury to any part, regardless of angle at which the plug is pulled or -jerked from the receptacle. Another advantage is that all of the relectric contacts and connecting p arts` are made large enough to carry more current than is required, and no heating of the parts occurs.

Having thus described my invention, what' I claim is:

1. The combination of a socket block having separated cavities in which are respectively located spring contacts, each contact being composed of spring arms suitably separated, and a socket plug equipped with electrodes adapted tovengage the spring contacts of the block, said block having recesses formed therein upon opposite sides of the contacts, the bottoms of the recesses being located in the rear of the portions of the contacts engaged by the said electrodes, the plug also having projections adapted to engage the recesses formed in the block, said projections and the bottoms of said recesses forming bearing surfaces when the plug is rocked upon the socket block, the block and plug having side bearing faces located forward of the bottoms of the upper and lower recesses of the block, substantially as described.

'2. In a charging device for electric vehicles, the combination of a socket block comprising 'a casing having a non-conducting iilling provided with parallel cavities which terminate in passages extending through the rear of the casing; plates cmbedded at the bottom of said cavities, circuit terminals in the passages extending into said plates and spring contacts removably secured to said circuit terminals said terminals having circuit wires connected thereto.

3. In a charging device for electric Vehicles a socket block comprising an open front metal casing having parallel hollow rear extensions, a non-conducting lling in said casing having parallel front cavities terminating in passages through said extensions, metal plates embedded at the bottoms of said cavities, having taperedaper-Y tures, metal circuit terminals in the passages having tapered ends extending into the said, apertures, spring contacts supported by said plates and removably secured thereto, said terminals having circuit wires connected therewith. v

4. In a charging device for electric vehicles, a socket block comprising a metal open front casing having parallel hollow rear extensions, a core of insulating material in said casing having parallel front cavities terminating inpassages extending through said extensions, metal plates embedded at the bottom of said cavities having tapered apertures, circuit terminals in said passages having tapered ends extending into said apertures, spring contacts supported by said plates, means for removably securing the contacts to the circuit terminals, said terminals having circuit wires connected therewith, and means surrounding the Wires for sealing the outer ends of said passages.

' 5. In a charging device for electric vehicles, a member adapted to be secured to the vehicles, comprising a metal casing open atv its front, and having parallel hollow' separated rear extensions, a non-conducting core in said casing having parallel front cavities terminating. in passages extending through said-extensions, terminals at the bottom of said cavities, substantially U-shaped, spring contacts removably secured to said terminals, said terminals having circuit wires connected therewith, non-conducting closures upon the outer ends of said extensions, which closely surround the said circuit wires, and means for securing said closures upon the ends of the said extensions.

6. In a charging device for electric ve? hicles,l a socket block comprising a metal casing open at the front, and having hollow rear extensions, a non-conducting core in said casing having separated cavities terminatingl in passages extending through said extensions, terminals in said core at the bottom of the cavities, having circuit wires connected therewith, substantially U-shaped, spring contact removably7 secured to said terminals, and means surrounding said wires for sealing the open ends of said passages.

7. In a charging device for electrically operated vehicles, .the combination with a battery and its supporting frame, of a metal l casing, secured to the under side thereof hav'-y ing an open front and tubular 'extensions on spring contacts removably secured to said terminals, and' bearingl against said plates,` circuit wires. attached to said terminals and. -leading to said battery, non-conducting closures for the-ends of saidztubular extensions and a clamp for holding said closures on said extensions, said closures having apertures which t tightly around the circuit Wires. c

In testimony whereof I afIx my signature in the presenceo two witnesses.

Witnesses:

\ MARY E. DAVIS,

IDA L. DAvIs. l

JASPER N. DAvrs.

ends whichA enterv said tapered apertures, 

